Investments - Amortized Cost and Estimated Fair Value, Net of Credit Loss Allowance, of Available-For-Sale Securities by Contractual Maturity (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Amortized cost
Due in one year or less	$ 56,875
Due after one year through five years	435,531
Due after five years through ten years	174,031
Due after ten years	309,921
Amortized cost	976,358
Estimated fair value
Due in one year or less	55,714
Due after one year through five years	414,012
Due after five years through ten years	167,272
Due after ten years	283,954
Estimated fair value	$ 920,952